11. Runtime Environment.   

Most languages have various forms of Run-time support. 



       Procedure Calls.  
       Activation Record.  
       Data Lifetime.  
       Run Time Support.  
       Support for parameter checking.  
       Support for Non-Local goto's.  
       Real Stack Machines.
Surprise!!

The amount and kind of Run-time support varies from language to language and from Operating System to Operating System.